Neat way to get aws api gateway lambda url and put it in serverless.yaml to store it as an environment variable on the lambda function

serverless.yaml

# Neat way to get aws api gateway lambda url and put it in serverless.yaml to store it as an environment variable on the lambda function:
provider:
  name: aws
  runtime: nodejs12.x
  stage: ${env:STAGE}
  region: ${env:REGION}
  environment:
    CI_URL:
      {
        "Fn::Join":
          [
            "",
            [
              " https://",
              { "Ref": "ApiGatewayRestApi" },
              ".execute-api.${self:provider.region}.amazonaws.com/${self:provider.stage}/",
            ],
          ],
      }